1. Field of the Invention
The present invention is for an improved low tension primary cable for automotive use.
2. Description of the Related Art
Among the technological developments regarding the automotive industry, there are processes focused towards the manufacturing of low tension primary cable for automotive vehicle use.
The requirements of the automotive industry, world-wide, for materials to be used in the short term (year 2000), are based on the following aspects:
trends in the automotive market at world level;
alternatives to fulfill the requirements of the automotive industry;
present and future norm and specifications of the automotive industry; and
commercially available materials that, according to their properties, can fulfill the automotive cable requirements.
The trends in the automotive industry have been focused towards weight reduction in order to reach a lower demand for fuel. On the other hand, the demand for vehicles that offer better safety, luxury and comfort, and the consequent need for cables for the various additional circuits, have increased rapidly and will continue to increase in the coming years.
Conductor diameter reduction, while maintaining the same mechanical characteristics as the conductors presently used in the automotive harnesses, is the alternative chosen by the designers and it will continue to be the main trend during the coming years. This makes it necessary to resort to conductor materials more mechanically resistant than copper, keeping an adequate balance between mechanical resistance and electrical conductivity in order to meet the specifications.
Presently there are two specification proposals with regard to an automotive cable that covers the previously described characteristics, the proposals being as follows:
Norm SAE J-1678 xe2x80x9cLow Tension, Ultra Thin Wall Primary Cablexe2x80x9d
FORD Engineering Specificationxe2x80x94xe2x80x9cCable, Primary Low Tension 0.25 mm and 0.15 mm Wallxe2x80x9d.
The prior art does not describe the material with which conductors have to be manufactured, but establish a minimum breaking load as well as a maximum electrical resistance; in this case, the present invention encompasses the 24 and 26 AWG conductors, which present as design condition a seven-wire strand symmetrical formation.
Presently, the conductor used for gauges below 22 AWG are manufactured from 100% copper alloy which must have a mechanical and electrical resistance that meets the above specification.
It is thus an object of the present invention to produce:
A flexible automotive electrical conductor of high mechanical strength, with a seven-wire strand symmetrical construction, i.e., to use a high strength wire of copper clad steel in the center and 6 hard electrolytic tough pitch (ETP) copper wires in the periphery. With regard to 24 AWG gauge conductor, the 7 wires are 32 AWG gauge; with regard to the 26 AWG gauge conductor, the center wire is 33 AWG gauge, while the 6 peripheral wires are 34 AWG gauge.